At present, the intracavity diaphragming method is usually used for the selection of transverse modes of gas laser cavity with a hard diaphragm being placed inside the cavity. Its position and size are determined theoretically. Narrowing of the working canal of a gas-discharge tube to the necessary dimension may also be used as a diaphragm. The above selection method has a number of disadvantages, essentially affecting manufacture of the device and its parameters. The aim of this work is to investigate the possibility of transverse mode selection in a gas laser cavity with methods of laser technology. This approach to selection mode problem differs from previously known ones in that the selection process takes place in the assembled emitter.